In many bird
species, it's easy to tell males from females because the plumage is
different. Not so with eagles! However, we can use size measurements
from different parts of the eagle's body to determine the gender of the
eagles we capture. Female eagles generally have larger wings, feet, talons,
beak, etc. A biologist by the name of Bortolotti discovered that 2 size
measurements show the greatest separation of male and female. The two
measurements are:

beak depth
and

hallux
(toe claw) length

These measurements
can be used in the following formula:

Sex
= (bill depth x 0.392) + (hallux length x 0.340) -27.694

If the
answer is POSITIVE, the eagle is a FEMALE.

If the
answer is NEGATIVE, the eagle is a MALE.

Here are the
key measurements from 6 eagles, plus their weights. Can you determine
the gender of these birds yourself?